Method of making longan seed extract

ABSTRACT

A method of making longan seed extract is provided with choosing an extraction solvent; heating the extraction solvent to a first predetermined temperature; adding pulverized longan seed to the extraction solvent to prepare a solution; maintaining the solution at a second temperature for a predetermined period of time to obtain an extracted substance; filtering the extracted substance; and drying and cooling the filtered extracted substance to produce an extract.

CROSS REFERENCE TO RELATED APPLICATIONS

This nonprovisional utility application is a divisional application ofand claims the benefit under 35 U.S.C.§120 to co-pending U.S.application Ser. No. 13/382,907 filed Mar. 8, 2012, all of which areincorporated, in their entirety, by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to extraction techniques and more particularly toa method of making longan seed extract.

2. Description of the Related Art

(1) Inflammation is part of the complex biological response of vasculartissues to harmful stimuli, such as pathogens, damaged cells, orirritants. Inflammation is a protective attempt by the organism toremove the injurious stimuli and to initiate the healing process.Inflammation is not a synonym for infection, even in cases whereinflammation is caused by infection. Although infection is caused by amicroorganism, inflammation is one of the responses of the organism tothe pathogen. However, inflammation is a stereotyped response, andtherefore it is considered as a mechanism of innate immunity. Contentsof inflammation comprise nitric oxide (NO), tumor necrosis factor (TNF),interleukin (IL), granulocyte colony stimulating factor (G-CSF),monocyte colony stimulating factor (M-CSF), granulocyte-monocyte colonystimulating factor (GM-CSF), and lymphotoxini (LT) such as TNF-α andTNF-β.

Without inflammation, wounds and infections would never heal. Similarly,progressive destruction of the tissue would compromise the survival ofthe organism. However, chronic inflammation can also lead to a host ofdiseases, such as hay fever, periodontitis, atherosclerosis, andrheumatoid arthritis. It is for that reason that inflammation isnormally closely regulated by the body.

Typically, antibiotics, non-steroidal anti-inflammation drugs (NSAIDs),and anti-histamine drugs are used to treat inflammation and they improvesymptoms. However, side effects are also reported.

(2) Gout is a medical condition usually characterized by recurrentattacks of acute inflammatory arthritis, e.g., a red, tender, hot,swollen joint. Goat can be hypercuricemia, recurrent acutemonoarthrities, and tophi. Gouty nephropathy is the symptom of seriousgoat. The metatarsal-phalangeal joint at the base of the big toe is themost commonly affected. However, it may also present as tophi, kidneystones, or urate nephropathy. It is caused by elevated levels of uricacid in the blood which crystallize and are deposited in joints,tendons, and surrounding tissues.

Hypercuricemia is the main cause of gout. About 5-18.8% patientssuffering hypercuricemia may have gout in the end period. It is fatal insome cases.

Uricase differential spectrophotometric method can be used to curehyperuricemia. Hyperuricemia is a level of uric acid in the blood thatis abnormally high. In humans, the upper end of the normal range is 360μmol/L (6 mg/dL) for women and 400 μmol/L (6.8 mg/dL) for men. Manyfactors contribute to hyperuricemia including genetics, insulinresistance, hypertension, renal insufficiency, obesity, diet, use ofdiuretics, and consumption of alcoholic beverages.

Hyperuricemia has four stages including asymptomatic hyperuricemia,acute gouty arthritis, inter-critical gout, and chronic tophaceous gout.

Diagnosis is confirmed clinically by the visualization of thecharacteristic crystals (e.g., monosodium urate crystal) in joint fluid.Shown negative birefringent means gout symptom. Other parts of a patientincluding toes, feet, and ankles can be also observed for gout symptom.

Treatment with steroids or colchicine improves gout symptoms. Once theacute attack has subsided, levels of uric acid are usually lowered vialifestyle changes, and in those with frequent attacks allopurinol orprobenecid provide long-term prevention.

Precipitation of uric acid crystals, and conversely their dissolution,is known to be dependent on the concentration of uric acid in solution,pH, sodium concentration, and temperature. Established treatmentsaddress these parameters.

Uricosuric agents are substances that increase the excretion of uricacid in the urine, thus reducing the concentration of uric acid in bloodplasma. In general, this effect is achieved by action on the proximaltubule. Drugs that reduce blood uric acid are not all uricosurics. Blooduric acid can be reduced by administered uricosuric agents for seven toten days gradually increased in amount. Other drugs such as probenecidand benzbromarone can also be used.

Treatment with xanthine oxidase inhibitor, allopurinol, hypoxanthine,and xanthine oxidase improves symptoms. Also, mercaptopurine orazathioprine can be used to treat gout but caution should be taken dueto its side effects.

(3) Wound healing is an intricate process in which the skin repairsitself after injury. In normal skin, the epidermis (i.e., outermostlayer) and dermis (i.e., inner or deeper layer) exists in a steady-stateequilibrium, forming a protective barrier against the externalenvironment. Once the protective barrier is broken, the normal processof wound healing is immediately set in motion. The classic model ofwound healing is divided into four sequential phases: hemostasis,inflammatory, proliferative, and remodeling. Upon injury to the skin, aset of complex biochemical events takes place in a closely orchestratedcascade to repair the damage. Within minutes post-injury, plateletsaggregate at the injury site to form a fibrin clot. This clot acts tocontrol active bleeding.

Growth factors related to wound healing include fibroblast growth factor2 (FGF2), platelet-derived growth factor (PDFG), epidermal growth factor(EFG), keratinocyte growth factor (KGF), transforming growth factor-α(TGF-α), transforming growth factor-β (TGF-β), and vascular endothelialgrowth factor (VEGF). These growth factors including PDFG, EFG, TGF-β,and VEGF are secreted by cells. Further, PDGF can absorb macrophages andfibroblasts and facilitates matrix protein growth. EGF can autocrine forgrowth. TGF-β can facilitate fibroblasts growth. VEGF can facilitateproangiogenic matrix growth and accelerate monocyte movement. Thesefactors are closely related to wound healing.

In the inflammatory phase, bacteria and debris are phagocytosed andremoved, and factors are released that cause the migration and divisionof cells involved in the proliferative phase. The proliferative phase ischaracterized by angiogenesis, collagen deposition, granulation tissueformation, epithelialization, and wound contraction. In angiogenesis,new blood vessels are formed by vascular endothelial cells. Infibroplasia and granulation tissue formation, fibroblasts grow and forma new, provisional extracellular matrix by excreting collagen andfibronectin.

The invention discussed below is novel and nonobvious as far as thepresent inventor is aware.

SUMMARY OF THE INVENTION

It is therefore one object of the invention to provide an extractionmethod comprising the steps of (1) choosing an extraction solvent; (2)heating the extraction solvent to a first predetermined temperature; (3)adding pulverized longan seed to the extraction solvent to prepare asolution; (4) maintaining the solution at a second temperature for apredetermined period of time to obtain an extracted substance; (5)filtering the extracted substance; and (6) drying and cooling thefiltered extracted substance to produce an extract.

In a first aspect of the invention, the extraction solvent is eitherwater or inorganic compound.

In a second aspect of the invention, the inorganic compound is a solventhaving a predetermined volume concentration of ethanol.

In a third aspect of the invention, the predetermined volumeconcentration of ethanol is about 20-95%.

In a fourth aspect of the invention, the first predetermined temperatureis about 70-90° C.

In a fifth aspect of the invention, the second predetermined temperatureis about 70-90° C.

In a sixth aspect of the invention, the predetermined period of time isabout 1-3 hours.

In a seventh aspect of the invention, the extract comprises corilagin,ellagic acid, and gallic acid.

In an eighth aspect of the invention, the longan seed extraction cancure inflammation.

In a ninth aspect of the invention, the longan seed extraction can curehyperuricemia.

In a tenth aspect of the invention, the longan seed extraction can healwound.

In an eleventh aspect of the invention, the longan seed extraction caninhibit microorganism growth.

In a twelfth aspect of the invention, the longan seed extraction has thefollowing advantages including curing inflammation, curinghyperuricemia, healing wound, and inhibiting microorganism growth.

The above and other objects, features and advantages of the inventionwill become apparent from the following detailed description taken withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a chart of results obtained by processing a solutioncomprising gallic acid, corilagin, and ellagic acid chosen as a controlgroup according to the invention by means of an HPLC apparatus;

FIG. 1A shows the structural formulas of corilagin, gallic acid, andellagic acid;

FIG. 1B is a table showing conditions of operating the HPLC apparatus;

FIG. 2 is a graph of results obtained by processing a longan seedextract comprising gallic acid, corilagin, and ellagic acid chosen as acontrol group according to the invention by means of an HPLC apparatus;

FIG. 2A is a table showing results of original IL-β and after stressIL-β in the anti-inflammation test;

FIG. 3 plots TNF-α versus IL-β for LPS, longan seed extract, longan seedextract after one-week, and control group;

FIG. 3A is a table showing results of original TNF-α and after stressTNF-α in the anti-inflammation test;

FIG. 4 plots the effect of decreasing serum of SD rats for treatmentgroup, longan seed extract group, and control group;.

FIG. 4A is a table of uric acid concentrations of control group,treatment group and longan seed extract group for anti-gout experiment;

FIG. 5 plots the number of Escherichia coli for control group andtreatment group;

FIG. 5A plots the number of staphylococcus aureus for control group andtreatment group;

FIG. 5B is a table showing results of anti-gout experiment with respectto xanthine oxidase and other samples;

FIG. 6 plots the number of propionibacterium acne for control group andtreatment group;

FIG. 6A is a table showing results of toxicity test by subjecting toconsecutive oral feeding;

FIG. 7 plots the number of Trichophyton rubrum for control group andtreatment group;

FIG. 7A is a table showing results of micro-organisms inhibition withrespect to Escherichia coli and Staphylococcus aureus;

FIG. 8 plots growth times versus time for crystal violet havingdifferent dose percentages;

FIG. 8A is a table showing results of micro-organisms inhibition withrespect to propionibacterium acne;

FIG. 9 plots FN for 0% longan seed extract, 5% longan seed extract, and10% longan seed extract;

FIG. 9A is a table showing results of micro-organisms inhibition withrespect to Trichophyton rubrum;

FIG. 10 is a table showing results of growth factors when subjecting tocrystal violet dyeing method by using different doses; and

FIG. 11 is a table showing results when subjecting to ELISA test.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 11, a method of making longan seed extract inaccordance with the invention comprises the following steps:

(a) An extraction solvent such as water or inorganic compound is chosen.In this embodiment, a solvent having 20-95% of ethanol is chosen as theextraction solvent.

(b) The extraction solvent is heated to a temperature of about 70-90° C.

(c) Pulverized longan seed is added to the extraction solvent to preparea solution.

(d) The solution is maintained at a temperature of about 70-90° C. forabout 1 to 3 hours for extraction.

(e) The extracted substance is filtered.

(f) The filtered extracted substance is dried at a low temperature andlow atmospheric pressure environment.

(g) Finally, longan seed extract is obtained.

Above steps of the invention are done in a high performance liquidchromatography (HPLC) apparatus. The extract is comprised of gallicacid, corilagin, and ellagic acid. The structural formulas of gallicacid, corilagin, and ellagic acid are shown in FIG. 1A. Further,equipment and conditions of the HPLC apparatus are shown in FIG. 1B.

The solution comprising gallic acid, corilagin, and ellagic acid ischosen as a control group. The solution is processed by the HPLCapparatus and its results are shown in FIG. 1. Retention time of gallicacid of 42.42 μg/ml is 14.409 minutes, retention time of corilagin of52.72 μg/ml is 43.304 minutes, and retention time of ellagic acid of22.4 μg/ml is 63.489 minutes respectively. The longan seed extract isprocessed by the HPLC apparatus and its results are shown in FIG. 2.Peaks of the longan seed extract have retention time of 14.461, 43.302,and 63.476 minutes respectively. Contents of the longan seed extract arethe same as that of the solution (i.e., gallic acid, corilagin, andellagic acid).

Symptoms improvements by treating with the longan seed extract of theinvention are discussed in the following experiments:

Experiment 1

Treatments with longan seed extract obtained from a solvent having 50%of ethanol, longan seed extract A obtained from a solvent having 100%pure water, and longan seed extract obtained from a solvent having 20%of ethanol improve inflammation symptoms as discussed below.

24 Sprague Dawley (SD) rats are grouped into nine groups of different SDrats in which one group is chosen as control group and the remaininggroups chosen as treatment groups. It is noted that all SD rats are malein the invention. Each SD rat has a weight of 200-250 g. Roomtemperature is kept at 23° C. Room is kept bright for 12-hour and darkfor next 12-hour repeatedly. Water is treated by reverse osmosis.

SD rats in the control group is fed with water only.

Longan seed extract is oral fed to the SD rats of a first treatmentgroup in the weight of 0.5 g/Kg of SD rat. After one week, LPS(lipopolysaccharides) of 2.5 mg/Kg of SD rat is abdomen injected intoeach SD rat. Another one day is waited.

Longan seed extract is oral fed to each SD rat of a second treatmentgroup in the weight of 0.5 g/Kg of SD rat, waiting for one week, LPS of2.5 mg/Kg of SD rat is abdomen injected into each SD rat, and waitingfor 48 hours.

LPS of 2.5 mg/Kg of SD rat is abdomen injected into each SD rat of athird treatment group, waiting for 24 hours, and oral feeding longanseed extract A of 0.5 g/Kg of SD rat to each SD rat.

LPS of 2.5 mg/Kg of SD rat is abdomen injected into each SD rat of afourth treatment group, waiting for 24 hours, and oral feeding longanseed extract B of 0.5 g/Kg of SD rat to each SD rat.

LPS of 2.5 mg/Kg of SD rat is abdomen injected into each SD rat of afifth treatment group, waiting for 24 hours, and oral feeding longanseed extract of 0.5 g/Kg of SD rat to each SD.

LPS of 2.5 mg/Kg of SD rat is abdomen injected into each SD rat of asixth treatment group, waiting for 48 hours, and oral feeding longanseed extract of 0.5 g/Kg of SD rat to each SD rat.

LPS of 2.5 mg/Kg of SD rat is abdomen injected into each SD rat of aseventh treatment group, and waiting for 24 hours.

Oral feeding longan seed extract of 0.5 g/Kg of SD rat to each SD rat ofan eight treatment group.

After one night of abstaining from food and drink, ether as anesthesiaagent is administered to each SD rat. Next, serum from arterial blood ofthe SD rat is withdrawn for check by using an Enzyme-linkedimmunosorbent assay (ELISA) test. It is noted that data obtained by theexperiment is subject to ANOVA (one-way analysis of variance).

As shown in columns “IL-β (ng/L) original” and “IL-β (ng/L) afterstress” of FIG. 2A, oral feeding of longan seed extract and abdomeninjection of LPS can enhance the immune system of the SD rats. As shownin columns “TNF-α (ng/L) original” and “TNF-α (ng/L) after stress” ofFIG. 3A and FIG. 3, oral feeding of longan seed extract and subsequentabdomen injection of LPS as well as only oral feeding of longan seedextract can enhance the capability of resisting inflammation of the SDrats.

Experiment 2

Treatments with longan seed extract obtained from a solvent having 50%of ethanol improve gout symptoms as discussed below.

24 SD rats are grouped into three groups of eight SD rats in which firstgroup is chosen as control group, second group chosen as treatmentgroup, and third group chosen as longan seed group. Each SD rat has aweight of 200-250 g. Room temperature is kept at 23° C. Room is keptbright for 12-hour and dark for next 12-hour repeatedly. Water istreated by reverse osmosis.

SD rats in the control group is fed with water only.

Hypoxathine in the weight of 300 mg/Kg of SD rat and oxonic acid in theweight of 250 mg/Kg of SD rat are oral fed to the SD rats of thetreatment group. Hypoxathine in the weight of 300 mg/Kg of SD rat,oxonic acid in the weight of 250 mg/Kg of SD rat, and longan seed of 0.1wt % are oral fed to the SD rats of the longan seed group.

After one night of abstaining from food and drink, ether as anesthesiaagent is administered to each SD rat. Next, serum from arterial blood ofthe SD rat is withdrawn for checking blood concentrations of uric acidby using Ciba-cornint 550. It is noted that data obtained by theexperiment is subject to ANOVA.

As shown in FIGS. 4 and 4A, longan seed extract obtained from a solventhaving 50% of ethanol lower about 32% of blood concentrations of uricacid of SD rats.

Experiment 3

50 mmol/L of xanthine is prepared by using a buffer solution called PBS(phosphate buffered saline). 0.1-0.2 unit/ml of xanthine oxidase isprepared by using PBS. Following samples are prepared: (1) Preparationof pure water and preparation of longan seed extract therefrom. (2)Preparation of solution having 20% ethanol and preparation of longanseed extract therefrom. (3) Preparation of solution having 50% ethanoland preparation of longan seed extract therefrom. (4) Preparation ofsolution having 95% ethanol and preparation of longan seed extracttherefrom. Allopurinol is taken as a positive control group. Xanthineoxidase is added to the control group. After five minutes, xanthine isadded to the control group. Water is added to a blank control group.Xanthinie oxidase is added to each sample. After five minutes, xanthineis added to each sample. A spectrometer is used to emit light ofwavelength of 290 nm to impinge on the samples and the control groups.Light absorption change is measured every 20-second for five minutes.Finally, enzyme activity is calculated. Xanthine oxidase inhibitionratio is defined by 1 minus enzyme activity of treatment group dividedby enzyme activity of control group. As shown in FIG. 5B, a maximum of60% xanthine oxidase inhibition ratio can be obtained.

Experiment 4

Gout toxicity elimination is tested below. Material is longan seedextract.

In an acute toxicity test, there are two groups each having 8-10 SDrats. Food is abstained from the groups but water is not abstained forone night. Oral feeding longan seed extract of 1 g/kg and 3 g/kg, andde-ionized water 1 ml/100 g to each SD rat for 28 consecutive days inwhich observing weight of each SD rat twice per day and weight of eachSD rat is measured once per week. Thereafter, food is abstained from theSD rats for one night. Ether as anesthesia agent is administered to eachSD rat. Next, serum from arterial blood of the SD rat is withdrawn forchecking GOT, GPT (Glutamate Pyruvate Transaminase), albumin, globulin,and greatinine by using Ciba-cornint 550. It is noted that data obtainedby the experiment is subject to ANOVA. Further, Dunnett check isconducted with value P less than 0.01 as great improvement.

Results are discussed below.

Acute toxicity test aims at obtaining a maximum sample in oneadministration that causes deaths of half of the tested animals. 1.0ml/100 g of SD rat and 450 mg/ml concentration are the maximum amountper sample. 15 g/kg is the standard sample. Longan seed extract of 15g/kg is administered to each of ten SD rats. Observation for 14 days. Nodeaths occur. Sample of LD50 is greater than 15 g/kg causing deaths ofhalf of the SD rats. No significant differences are observed between SDrats of the control group and that of the treatment group after 14 days.

28-day toxicity test aims at finding a sample that causes death of halfSD rats. Further, one-fifth of the sample is taken as a maximum sample.3 g/kg and 1 g/kg are taken as the maximum samples. Two treatment groupseach have 8-1 SD rats. Oral feeding 3 g/kg of longan seed extract to SDrats of one treatment group and oral feeding 1 g/kg of longan seedextract to SD rats of the other treatment group are performed for 28consecutive days. Thereafter, no deaths are found and there are nosignificant weight differences between the SD rats of treatment groupsand the SD rats of a control group.

Serum from arterial blood of the SD rats of the treatment groups iswithdrawn for check. As shown in FIG. 6A, there are no significant serumcomposition differences between the SD rats of treatment groups and theSD rats of a control group. Further, there are no significant weightdifferences of the liver and the kidneys between the SD rats oftreatment groups and the SD rats of a control group. It is concludedthat the administration of longan seed extract does not affect weight oforgans of an SD rat, organs such as heart, liver, kidneys, testes, etc.of the SD rats of treatment groups functions normally, and no adverseeffects to SD rats is confirmed.

Experiment 5

This is a sterilization experiment. Materials include 2.5 mg/ml oflongan seed extract. A solution is made y adding water (obtained byreverse osmosis) to the longan seed extract. The solution is nextfiltered by a mini pore to produce a sterilized PBS.

Escherichia coli and Staphylococcus aureua are grown in an LB broth at37° C. for 16 hours. Next, 1× PBS is used to wash the grown Escherichiacoli and Staphylococcus aureua for three times in which a rotation of3,000 rpm/minute for ten minutes is performed after each washing. Aspectrometer is used to test OD value of the washed Escherichia coli andStaphylococcus aureua. Finally, Escherichia coli and Staphylococcusaureua having OD value of 0.3 is added to 1× PBS to prepare a solutionwhich is in turn diluted with pure water to form a solution having theamount of Escherichia coli and Staphylococcus aureua 10% less than thatprior to dilution. Next, the solution is reacted at 37° C. for one hour.Next, adding 5, 10, 20, 50, and 100 μl to the LB broth. Next, thesolution is reacted at 37° C. for 18 hours. Next, calculate the numberof Escherichia coli and Staphylococcus aureua. The solution treated withPBS is taken as treatment group and that treated with water (obtainedfrom reverse osmosis) is taken as control group.

Above test is performed three times and results thereof are shown inFIGS. 5, 5A and 7A. It is found that the number of Escherichia coli andStaphylococcus aureua of the treatment group is greatly decrease ascompared with that of the control group. It is concluded that longanseed extract has the effect of killing Escherichia coli andStaphylococcus aureua. It is useful for inhibiting acne.

Experiment 6

This is also a sterilization experiment. Above sterilized PBS is used.Propionibacterium acne is grown in a BAP broth at 37° C. for 48 hours.Next, 1× PBS is used to wash the grown propionibacterium acne for threetimes in which a rotation of 3,000 rpm/minute for ten minutes isperformed after each washing. A spectrometer is used to test OD value ofthe washed propionibacterium acne. Finally, propionibacterium acnehaving OD value of 0.3 is added to 1× PBS to prepare a solution which isin turn diluted with pure water to form a solution having the amount ofpropionibacterium acne 10% less than that prior to dilution. Next, thesolution is reacted at 37° C. for one hour. Next, adding 5, 10, 20, 50,and 100 μl to the BAP broth. Next, the solution is reacted at 37° C. for48 hours. Next, calculate the number of propionibacterium acne. Thesolution treated with PBS is taken as treatment group and that treatedwith water (obtained from reverse osmosis) is taken as control group.

Above test is performed three times and results thereof are shown inFIGS. 6 and 8A. It is found that the number of propionibacterium acne ofthe treatment group is greatly decrease as compared with that of thecontrol group. It is concluded that longan seed extract has the effectof killing propionibacterium acne. It is useful for inhibiting acne.

Experiment 7

This is also a sterilization experiment. Above sterilized PBS is used.Trichopyhton rubrum is grown in an IMA (Inhibit mold agar) broth at 30°C. for 96 hours. Next, 1× PBS is used to wash the grown Trichopyhtonrubrum for three times in which a rotation of 3,000 rpm/minute for tenminutes is performed after each washing. A spectrometer is used to testOD value of the washed Trichopyhton rubrum. Finally, Trichopyhton rubrumhaving OD value of 0.1 is added to 1× PBS to prepare a solution which isin turn diluted with pure water to form a solution having the amount ofTrichopyhton rubrum 10% less than that prior to dilution. Next, thesolution is reacted at 30° C. for one hour. Next, adding 5, 10, 20, 50,and 100 μl to the IMA broth. Next, the solution is reacted at 30° C. for96 hours. Next, calculate the number of Trichopyhton rubrum. Thesolution treated with PBS is taken as treatment group and that treatedwith water (obtained from reverse osmosis) is taken as control group.

Above test is performed three times and results thereof are shown inFIGS. 9 and 9A. It is found that the number of Trichopyhton rubrum ofthe treatment group is greatly decrease as compared with that of thecontrol group. It is concluded that longan seed extract has the effectof killing Trichopyhton rubrum. It is useful for inhibiting athlete'sfoot.

Experiment 8

This is a wound healing experiment. Materials include solving 5 g longanseed extract in 250 ml water to make a solution. The solution is theninitially filtered by a filter paper. And in turn, the solution isfiltered by a filter of 0.45 μm and another filter of 0.22 μmsequentially. A solution having 0 wt % of longan seed extract, asolution having 0.25 wt % of longan seed extract, a solution having 2.5wt % of longan seed extract, a solution having 5.0 wt % of longan seedextract, and a solution having 10.0 wt % of longan seed extract are madefor growing human epidermal keratinocytes (HEKa-C005-5C) as detailedbelow

Cells growth: 1×10⁴ cells/ml human epidermal keratinocytes(HEKa-C005-5C) is prepared. KC (keratinocytes) andpenicillian-streptomycin available from Cascade biologics, USA are grownin an incubator having 5% CO₂ at 37° C. Cells grown in this stage arecalled first cells. KC and penicillian-streptomycin are replenishedevery two days until the incubator is about 80% full of grown cells.Next, adding 0.25% trypsin-EDTA (ethylenediaminetetraacetate acid)solution having 0.25% trypsin and 0.02% EDTA. Next, it is reacted at 37°C. for 5 minutes. Cells grown in this stage called second cells. FloatedKC is washed with a solution having more than 10% clean water forneutralization. Next, the solution is poured into a centrifuge which isin turn rotated at 1,500 rpm for 10 minutes for removing fine solids.Next, KC and penicillian-streptomycin are used again to float cells.Next, the solution is diluted in a 1:3 ratio with water. Finally, cellsare grown in an incubator having 5% CO₂ at 37° C. Cells grown in thisstage called third cells.

Cells growth test is next performed by means of crystal violet.HEKa-C005-5C is grown for 24, 48, and 72 hours continuously. Next, amicroscope is used to observe cells growth. Clean water of 200 μl isused to wash the grown cells. Next, cells are fixed for 20 minutes by acells fixation solution. PBST of 200 μl is used to wash the grown cellstwice. Adding crystal violet of 100 μl into the solution to change colorin room temperature for 30 minutes. Next, clean water of 200 μl is usedto wash the grown cells trice. 1% SDS (sodium dodecyl sulfate) is usedto solve cells. Rotating the solution in room temperature for 1 hour.Crystal violet attached to cells are extracted. A spectrometer is usedto emit light of wavelength of 595 nm to impinge on the extract in orderto measure the OD value. Further, light of wavelength of 650 nm isemitted to impinge on the extract to change the OD value. Solutionwithout longan seed extract is taken as control group to obtain growthfactors.

Human epidermal keratinocytes growth factors are determined by means ofELISA. Human epidermal keratinocytes are collected. Growth factors ofthe collected human epidermal keratinocytes are determined by means ofcommercial kits. Microtitration plate of 96 well plates is chosen.Bovine serum albumin is used for inhibition. Next, PBS-Tween is used towash the microtitration plate. Clean solution of 100 μl is add forreaction at 37° C. for two hours. Next, PBS-Tween is used to was again.Next, rabbit-anti-growth factor Ab-HRP available from Chemicon,Temmecula, Calif. is added for reaction at 37° C. for two hours. Next,it is washed again. Next, colored substrate having O-phenyldiamine isadded. Next, 50 μl of 2N H₂SO₄ is added to stop reaction. Next, OD valueat wavelength 450 nm is measured. Finally, vascular endothelial growthfactor (VEGF) is determined

Results are shown in FIGS. 8 and 10. It is found that effects of crystalviolet dying method for determining growth factor can be observed bymeans of a microscope. It is shown that samples with 2.5%, 5.0% and 10%of dose can increase human epidermal keratinocytes growth factors morethan 1.25, 1.26 and 1.50 times as compared with control group.Particularly, the sample with 10% of dose having a p-value less than0.05 is advantageous because it means that 10% longan seed extract cangreatly increase human epidermal keratinocytes growth factors.

Results obtained by means of ELISA test are shown in FIGS. 9 and 11. Inthe columns “CI (collagen I) (μg/ml)” and “FN (fibronectin) (pg/ml)”,after adding 5% and 10% longan seed extract, VEGF is increased greatly(p<0.05). This means that wound treated with longan seed extract can bequickly healed.

It is envisaged by the invention that the advantages of healinginflammation, lowering uric acid, killing micro-organisms, increasinghuman epidermal keratinocytes growth, and helping wound healing withouthurting organs can be obtained.

While the invention has been described in terms of preferredembodiments, those skilled in the art will recognize that the inventioncan be practiced with modifications within the spirit and scope of theappended claims.

What is claimed is:
 1. A method for improving wound healing in a subject comprising administrating to the subject a pharmaceutically effective amount of an extract of longan seed.
 2. The method according to claim 1, wherein the extract of longan seed is prepared by extracting the longan seed with water or a hydrophilic solution.
 3. The method according to claim 2, wherein the hydrophilic solution comprises an alcohol.
 4. The method according to claim 3, wherein the alcohol comprises ethanol.
 5. The method according to claim 3, wherein the alcohol has a volume concentration about 20% to about 95%.
 6. The method according to claim 2, wherein the extracting is conducted at about 70° C. to about 90° C.
 7. The method according to claim 2, wherein the longan seed is pulverized.
 8. The method according to claim 1, which is for stimulating keratinocyte growth and/or stimulating vascular endothelial growth factor.
 9. The method according to claim 1, which is for increasing vascular permeability, stimulating proangiogenic matrix growth, accelerate monocyte movement and/or angiogenesis. 